1. Field of the Invention
The present invention relates to a warp-knit stringer tape for slide fasteners suitable for use on knit garments.
2. Prior Art
There are known various warp-knit stringer tapes for slide fasteners for use on knit garments such as cardigan sweaters which require the stringer tape not only to have a soft and smooth texture, but also to be stretchable, particularly longitudinally thereof. To this end, it has been proposed to use textured yarns in a warp-knit stringer tape in order to impart to the tape a smooth and soft texture. However, the prior stringer tape has only an inadequate degree of longitudinal stretchability, since the textured yarns are used only for the weft threads.
Yet, to use highly stretchable yarns in the knit structure of the tape causes the tape to become convex at one longitudinal edge along which a row of coupling elements is to be mounted. This is true because non-stretchable yarns must be used in the coupling-element-supporting tape edge portion in order to give it an adequate degree of mechanical strength and dimensional stability. From such curved tape it is difficult to obtain a proper slide fastener stringer, since the coupling-element-supporting tape edge portion is necessarily extended to become still more convex as a result of mounting the coupling elements therealong.